This invention relates to communication switching networks. This invention could also relate to other computer controlled networks or control systems such as process controls that might be used in a refinery, banking or other networks handling large amount of data or voice information.
Switching systems networks route thousands of calls, but generally require relatively little computational capability compared to the computational capabilities that are in now-commonly available microprocessors. One critical aspect of switching system reliability however is the control computer(s) that handles routing and switching of calls through the switching system. The typical control architecture in use today is a computer, co-located with the actual switching system. If the controlling computer fails, an entire switching system will be unable to process calls.
The recent advance of inexpensive, high-power microprocessors and the recent advent of high-speed data links now make it possible to locate high-powered computational capabilities at remote locations. Relatively inexpensive microprocessors can provide significant computer power. With the advent of fiber optic cable, for example, it is now possible to remotely provide substantial computer resources to remote locations.
A problem with prior art switching system architectures is the possibility of failure of a computer controlling a switching system. If such a computer does fail, either by natural disaster, an act of terrorism, hardware failure or software failure, neither the computer, nor any backup thereto, will be available to perform system-required computational tasks.
Another problem with prior art switching system control systems is the expense associated with maintenance. In communication networks comprised of numerous switching systems, continuous system availability requires that each system have a competent maintenance staff, which is unnecessary most of the time.
A method and an apparatus by which computers controlling a switching system can be centrally located, backed up, and where maintenance staff can also be centrally located would reduce the costs required to provide reliable computer resources for controlling switching systems. Maintenance staff could be reduced while improving system reliability. Instead of using costly, special purpose, highly reliable, fault-tolerant computers, less costly computers could be used without sacrificing network availability because control computer reliability can be achieved with several less expensive computers at several backup locations.